1. Field of the Invention
The present invention relates to an information processing apparatus that is capable of displaying maps and a position displaying method.
2. Related Background Art
Due to advances in mobile communications technologies in recent years, developments in devices that teach current locations of moving bodies are underway.
For example, a wandering aged person tracking system uses the personal handy-phone system (PHS) technology, and notifies a PHS base station that is located closest to a person (for example, a wandering aged person) who is carrying a mobile communications device of the location of the person. Since, PHS base stations are typically installed at intervals of several hundred meters, the position can be detected in several hundred meters.
Also, the global positioning system (GPS) use satellites to allow navigation, positioning, and other research throughout the world.
However, the conventional positioning technology that uses base stations and satellites to locate current positions entails the following problems.
(1) In the wandering aged person tracking system described above, the position of a person can be detected only within the range of the nearest station, and more precise, specific positioning cannot be provided. Also, the wandering aged person tracking system is currently installed at several locations throughout Japan, the system cannot be used throughout the world. The system cannot be used in areas where radio signals from base stations cannot reach even within Japan.
(2) The GPS needs to receive radio signals from a plurality of satellites; and the GPS cannot be used when radio signals cannot be received, for example, inside buildings or tunnels. Furthermore, due to the fact that position data sent from satellites may be intentionally degraded, an auxiliary system may be required to improve the positioning accuracy, which in turn increases the cost of the device.